1. Field of the Invention
This invention relates generally to the manufacturing of photovoltaic cells and particularly to assembly of a matrix of photovoltaic cells during manufacturing.
2. Description of the Prior Art
Photovoltaic cells (also commonly referred to as “solar cells”) have gained overwhelming popularity for a variety of applications in recent years, particularly in light of increasing utility costs and environmental concerns. Photovoltaic cells are generally assembled and encapsulated by manufacturers before being shipped to users for use into various applications. Flexible photovoltaic cells, which are a group of cells placed adjacently relative to each other but in a manner is flexible rather than rigid and are assembled by mounting the cells on flexible plastic substrate (or “semiconductor”), such as polyimide, PEEK or transparent conductive polyester film or on metal foil
A group of photovoltaic cells, i.e. matrix of cells, are interconnected, electrically and mechanically during manufacturing but are typically vulnerable to mechanical integrity issues related to the interconnected photovoltaic cells in addition to reduced electrical performance and lower yield causing increased manufacturing costs. These problems are further exacerbated when large numbers of flexible cells are to be positioned in precise alignment during manufacturing. Assembly of matrices requires alignment of the matrix of photovoltaic cells before the matrix is cured in an oven. During alignment however, because the cells are not uniform and have varying sizes, or the chuck used to align them is warped, alignment is not uniform and results in a non-flat surface, adversely impacting yield and reliability of the matrix.
Currently, one of the ways of aligning of a matrix assembly is done by taping the matrix to glass to align a matrix before it is interconnected, which leaves tape residue on the photovoltaic cell, is slow and inaccurate. Also, the interconnection of the cells of the matrix is not flat. Problems with other techniques include throughput or yield.
What is needed is a method and apparatus for reliable and accurate assembly of a matrix of flexible photovoltaic cells.